Whey protein

Studies in people

• Benefit

  Muscle strength in older adults²

  In older adults with frailty or sarcopenia, whey protein improved lean mass and physical function, but not in healthy older adults.

• Benefit

  Muscle strength in older women³

  In postmenopausal women, whey protein improved biceps curl strength and lower limb lean mass only with resistance training.

• Benefit

  Muscle loss with age⁴

  In older adults, leucine-enriched whey protein plus resistance training increased lean muscle mass, strength and physical performance.

• Benefit

  Muscle recovery after exercise⁵

  Whey protein may help young, healthy adults regain muscle strength after hard workouts, but scientists say more research is needed.

• No harm found

  Acne severity in men⁶

  In a six-month study of men with acne, whey protein did not make acne worse than a non-whey supplement.

• Benefit

  Muscle building after exercise⁷

  In studies of healthy adults, whey protein taken with exercise boosted muscle protein building, especially right after or before a workout.

• Open question

  Cancer treatment support⁸

  In people, whey protein did not clearly fight cancer, though it may help with muscle loss.

• Benefit

  Diet and Crohn's risk⁹

  In people, eating whey protein was linked to a lower risk of Crohn's disease.

• Benefit

  Muscle soreness after exercise¹⁰

  In teen swimmers, whey protein after hard swimming eased soreness at 24 hours versus water, but not versus carbs.

• Benefit

  Muscle loss with ageing¹¹

  In sarcopenic elderly people, whey protein with essential amino acids and vitamin D plus exercise increased fat-free mass and handgrip strength.

• Open question

  Kidney stone risk¹²

  In people, whey protein did not change average kidney stone risk factors, but some individuals' urine calcium rose.

• Benefit

  Muscle growth from exercise¹³

  In men doing four weeks of resistance training, whey protein led to bigger gains in muscle mass and strength.

• Benefit

  Muscle recovery after running¹⁴

  In runners, whey protein was linked to lower muscle damage markers after a marathon and better endurance.

• No harm found

  Thigh muscle and iron¹⁵

  In male triathletes, whey protein did not preserve thigh muscle thickness or raise iron stores.

• Benefit

  Bone and muscle strength in older men¹⁶

  In older men, whey protein plus supervised strength training improved bone density and muscle mass.

Animal and lab studies only

• Benefit

  Blood pressure²⁰

  Some whey protein pieces may help lower blood pressure, but they are weaker than blood pressure drugs.

Study type not stated

• Concern

  Kidney and liver health¹⁸

  Taking whey protein too much for a long time may affect the kidneys and liver.

• Benefit

  Baby formula digestion¹⁹

  Whey protein in baby formula is broken into smaller pieces to help babies digest it and grow.

How it’s made and used

• Salt content preference¹⁷

  A whey protein spread with added beta-glucan kept well for 28 days in the fridge, and women preferred the less salt version.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.